EP2090240B1 - Disposable motor-driven loading unit for use with a surgical cutting and stapling apparatus - Google Patents

Abstract

A self contained motor-powered disposable loading unit for use with a surgical cutting and stapling apparatus. The disposable loading unit may contain a battery that is retained in a disconnected position when the disposable loading unit is not in use and is moved to a connected position when the disposable loading unit is coupled to the surgical cutting and stapling apparatus to permit the motor to be selectively powered thereby. Indicators may be supported on the disposable loading unit to indicate when the axial drive assembly thereof is in a starting position and an ending position. Another indicator may be provided to indicate when the anvil assembly is in a closed position.

Description

FIELD OF THE INVENTION
• The present invention relates in general to endoscopic surgical instruments including, but not limited to, surgical cutting and stapling apparatuses that have disposable loading units that are capable of applying lines of staples to tissue while cutting the tissue between those staple lines and, more particularly, to improvements relating to such disposable loading units.
BACKGROUND
• Endoscopic surgical instruments are often preferred over traditional open surgical devices since a smaller incision tends to reduce the post-operative recovery time and complications. Consequently, significant development has gone into a range of endoscopic surgical instruments that are suitable for precise placement of a distal end effector at a desired surgical site through a cannula of a trocar. These distal end effectors engage the tissue in a number of ways to achieve a diagnostic or therapeutic effect (e.g., endocutter, grasper, cutter, staplers, clip applier, access device, drug/gene therapy delivery device, and energy device using ultrasound, RF, laser, etc.).
• Known surgical staplers include an end effector that simultaneously makes a longitudinal incision in tissue and applies lines of staples on opposing sides of the incision. The end effector Includes a pair of cooperating jaw members that, if the instrument is intended for endoscopic or laparoscopic applications, are capable of passing through a cannula passageway. One of the Jaw members supports a staple cartridge that has at least two laterally spaced rows of staples. The other jaw member defines an anvil having staple-forming pockets aligned with the rows of staples in the cartridge. The Instrument commonly includes a plurality of reciprocating wedges which, when driven distally, pass through openings in the staple cartridge and engage drivers supporting the staples to effect the firing of the staples toward the anvil.
• One type of surgical stapling apparatus is configured to operate with disposable loading units (DLU's) that are constructed to support a staple cartridge and knife assembly therein. Once the procedure is completed, the entire DLU is discarded. Such Instruments that are designed to accommodate DLU's purport to offer the advantage of a "fresh" knife blade for each firing of the instrument. Examples of such surgical stapling apparatuses and DLU's are disclosed inU.S. Patent No. 5,865,361 to Milliman et al.
• Such prior disposable loading units, however, require the clinician to continuously ratchet the handle to fire the staples and cut the tissue. There is a need for a surgical stapling apparatus configured for use with a disposable loading unit that is driven by a motor contained in the disposable loading unit. A prior art self-contained powered surgical apparatus Is known fromEP1839596A1. The two-part from ofclaim 1 is based on this document.
SUMMARY
• In one general aspect of various embodiments of the present Invention, there is provided a disposable loading unit for attachment to a surgical cutting and stapling apparatus. In various embodiments, the disposable loading unit comprises a carrier that supports a staple cartridge therein. An anvil assembly may be movably coupled to the carrier for selective movable travel between open and closed positions relative to the staple cartridge. An axial drive assembly is supported within the carrier such that it can move in a distal direction from a start position to an end position through the carrier and the staple cartridge. The axial drive assembly may also be retracted in a proximal direction from the end position back to the start position. A motor is supported within the carrier and constructed to drive the axial drive assembly in the distal and proximal directions. A battery is supported within the carrier and be coupled to the motor for supplying power thereto.
• In still another general aspect of various embodiments of the present invention, there is provided a disposable loading unit for attachment to a surgical cutting and stapling apparatus. The disposable loading unit includes a carrier that supports a staple cartridge therein. An anvil assembly is movably coupled to the carrier for selective movable travel between open and closed positions relative to the staple cartridge. A housing is coupled to the carrier and configured for removable operable attachment to the surgical stapling apparatus. An axial drive assembly is supported within the carrier and the housing to move in a distal direction from a start position to an end position through the carrier and the staple cartridge. The axial drive assembly may also be retracted in a proximal direction from the end position to the start position. A motor is supported within the carrier and configured to interface with the axial drive assembly to drive the axial drive assembly in the distal and proximal directions. A battery is supported within the carrier and coupled to the motor for supplying power thereto. The battery may be selectively movable between a disconnected position and connected positions in response to motions applied thereto by a portion of the surgical stapling apparatus.
• It is also disclosed a surgical cutting and stapling apparatus. The apparatus includes a handle assembly that operably supports a drive assembly therein that is constructed to impart drive motions and a retraction motion. A movable handle portion is operably supported on the handle assembly and configured to interface with the drive system such that manipulation of the movable handle causes the drive system to impart the drive motions. An elongated body protrudes from the handle assembly and has a distal end that is couplable to a disposable loading unit. The disposable loading unit comprises a carrier that has a staple cartridge supported therein. An anvil assembly is movably coupled to the carrier for selective movable travel between open and closed positions relative to the staple cartridge. An axial drive assembly is supported within the carrier such that the axial drive assembly may move in a distal direction from a start position to an end position through the carrier and the staple cartridge and also in a proximal direction from the end position to the start position. A motor is supported within the carrier and configured to interface with the axial drive assembly to drive the axial drive assembly in the distal and proximal directions. A battery is supported within the carrier and coupled to the motor for supplying power thereto. The battery is configured to interface with a portion of the elongated body to receive the drive motions therefrom upon manipulation of the moveable handle.
• These and other objects and advantages of the present invention shall be made apparent from the accompanying drawings and the description thereof.
BRIEF DESCRIPTION OF THE FIGURES
• The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention, and, together with the general description of various embodiments of the invention given above, and the detailed description of the embodiments given below, serve to explain various principles of the present invention.
• FIG. 1 is a perspective view of a disposable loading unit embodiment of the present invention coupled to a conventional surgical cutting and stapling apparatus.
• FIG. 2 is a cross-sectional view of the disposable loading unit ofFIG. 1 with several components shown in full view for clarity.
• FIG. 3 is a cross-sectional view of a proximal end of the disposable loading unit embodiment ofFIGS. 1 and2 with various components shown in full view for clarity.
• FIG. 4 is a schematic of a circuit embodiment of the disposable loading unit ofFIGS. 1-3.
• FIG. 5 is a cross-sectional view of the disposable loading unit ofFIGS. 1-3 when the disposable loading unit has been attached to the elongated body of the surgical instrument.
• FIG. 6 is a schematic view of the circuit illustrating the position of various components of the disposable loading unit after it has been attached to the surgical instrument.
• FIG. 7 is a cross-sectional view of the disposable loading unit ofFIGS. 1-6 when the drive beam has been moved to the anvil closed position.
• FIG. 8 is a schematic view of the circuit illustrating the position of various components of the disposable loading unit after the drive beam has been moved to the anvil closed position.
• FIG. 9 is a cross-sectional view of the disposable loading unit ofFIGS. 1-8 when the drive beam has been moved to its distal-most fired position.
• FIG. 10 is a schematic view of the circuit illustrating the position of various components of the disposable loading unit after the drive beam has been moved to its distal-most fired position.
• FIG. 11 is a cross-sectional view of the disposable loading unit ofFIGS. 1-10 as the drive beam is being returned to a starting position.
• FIG. 12 is a schematic view of the circuit illustrating the position of various components of the disposable loading unit as the drive beam is being returned to a start position.
DETAILED DESCRIPTION
• Turning to the Drawings, wherein like numerals denote like components throughout the several views,FIG. 1 depicts adisposable loading unit 16 of the present invention that is coupled to a conventional surgical cutting andstapling apparatus 10.
  The construction and general operation of a cutting andstapling apparatus 10 is described inU.S. Patent No. 5,865,361 . Thus, the present Detailed Description will not discuss the various components of theapparatus 10 and their operation herein beyond what is necessary to describe the operation of thedisposable loading unit 16 of the present invention.
• As the present Detailed Description proceeds, it will be appreciated that the terms "proximal" and "distal" are used herein with reference to a clinician gripping ahandle assembly 12 of thesurgical stapling apparatus 10 to which thedisposable loading unit 16 is attached. Thus, thedisposable loading unit 16 is distal with respect to the moreproximal handle assembly 12. It will be further appreciated that, for convenience and clarity, spatial terms such as "vertical", "horizontal", "up", "down", "right", and "left" are used herein with respect to the drawings. However, surgical instruments are used in many orientations and positions, and these terms are not intended to be limiting and absolute.
• As can be seen inFIG. 1, thedisposable loading unit 16 comprises atool assembly 17 for performing surgical procedures such as cutting tissue and applying staples on each side of the cut. Thetool assembly 17 includes acartridge assembly 18 that includes astaple cartridge 220 that is supported in acarrier 216. Ananvil assembly 20 may be pivotally coupled to thecarrier 216 in a known manner for selective pivotal travel between open and closed positions. Theanvil assembly 20 includes ananvil portion 204 that has a plurality of staple deforming concavities (not shown) formed in the undersurface thereof. Thestaple cartridge 220 houses a plurality of pushers or drivers (not shown) that each have a staple or staples (not shown) supported thereon. Anactuation sled 234 is supported within thetool assembly 17 and is configured to drive the pushers and staples in thestaple cartridge 220 in a direction toward theanvil assembly 20 as theactuation sled 234 is driven from the proximal end of thetool assembly 17 to thedistal end 220. SeeFIG. 2.
• Thedisposable loading unit 16 includes anaxial drive assembly 212 that comprises adrive beam 266 that may be constructed from a single sheet of material or, preferably, from multiple stacked sheets. However, thedrive beam 266 may be constructed from other suitable material configurations. The distal end ofdrive beam 266 may include avertical support strut 271 which supports aknife blade 280 and anabutment surface 283 which engages the central portion ofactuation sled 234 during a stapling procedure.Knife blade 280 may be generally positioned to translate slightly behindactuation sled 234 through a central longitudinal slot instaple cartridge 220 to form an incision between rows of stapled body tissue. Aretention flange 284 may project distally fromvertical strut 271 and support a camming pin or pins 286 at its distal end.Camming pin 286 may be dimensioned and configured to engagecamming surface 209 onanvil portion 204 to clampanvil portion 204 against body tissue. SeeFIGS. 5 and7. In addition, a leaf spring (not shown) may be provided between the proximal end of theanvil portion 204 and the distal end portion of thehousing 200 to bias theanvil assembly 20 to a normally open position. Thecarrier 216 may also have an elongated bottom slot therethrough through which a portion of thevertical support strut 271 extends to have asupport member 287 attached thereto
• As can also be seen inFIG. 1, thedisposable loading unit 16 has ahousing portion 200 that is adapted to snap onto or otherwise be attached to thecarrier 216. Theproximal end 500 ofhousing 200 may includeengagement nubs 254 for releasably engaging elongated body 14 of a surgical stapling apparatus.Nubs 254 form a bayonet type coupling with the distal end of the elongated body portion 14 of the surgical stapling apparatus as described inU.S. Patent No. 5,865,361.
• Thehousing 200 further includes aswitch portion 520 that movably houses abattery 526 therein. More specifically and with reference toFIG. 3, theswitch portion 520 of thehousing 200 defines abattery cavity 522 that movably supports abattery holder 524 that houses abattery 526 therein. As can be seen inFIG. 3, afirst battery contact 528 is supported in electrical contact with thebattery 526 and protrudes out through thebattery holder 524 for sliding engagement with theinside wall 523 of thebattery cavity 522. Similarly, asecond battery contact 530 is mounted in electrical contact with thebattery 526 and also protrudes out of thebattery holder 524 to slide along theinside wall 523 of thebattery cavity 522. Thebattery holder 524 has acontrol rod socket 532 therein configured to receive thedistal end 276 ofcontrol rod 52 when the proximal end ofdisposable loading unit 16 is coupled to the elongated body 14 ofsurgical stapling apparatus 10. As can also be seen inFIG. 3, a series ofcontacts 540, 542, 544 may be oriented within thewall 523 for contact with thebattery contacts 530. The purpose of thecontacts 540, 542, and 544 will be discussed in further detail below. As can also be seen inFIG. 3, a biasing member orswitch spring 550 is positioned within thebattery cavity 522 to bias thebattery holder 524 in the proximal direction "PD" such that when the disposable reload 16 is not attached to the elongated body 14, thebattery holder 524 is biased to its proximal-most position shown inFIG. 3. When retained in that "pre-use" or "disconnected" position byspring 550, thebattery contacts 528 and 530 do not contact any of thecontacts 540, 542, 544 within thebattery cavity 522 to prevent thebattery 526 from being drained during non-use.
• As can also be seen inFIG. 3, thehousing 200 further has amotor cavity 560 therein that houses amotor 562 and agear box 564. Thegear box 564 has anoutput shaft 566 that protrudes through ahole 572 in aproximal bulkhead 570 formed in thehousing 200. SeeFIG. 5. Theoutput shaft 566 is keyed onto or otherwise non-rotatably coupled to athrust disc 580. As can be seen inFIG. 5, thethrust disc 580 is rotatably supported within athrust disc cavity 582 formed between theproximal bulkhead 570 and adistal bulkhead 590 formed in thehousing 200. In addition, thethrust disc 580 is rotatably supported between aproximal thrust bearing 583 and a distal thrust bearing 584 as shown. As can also be seen inFIG. 5, thethrust disc 580 may be formed on a proximal end of adrive screw 600 that threadedly engages adrive nut 610 that is supported within anengagement section 270 formed on the distal end of thedrive beam 266. Theengagement section 270 may include a pair ofengagement fingers 270a and 270b that are dimensioned and configured to be received within a slot in thedrive nut 610 to non-rotatably affix thedrive nut 610 to thedrive beam 266. Thus, rotation of thedrive screw 600 within thedrive nut 610 will drive thedrive beam 266 in the distal direction "DD" or in the proximal direction "PD" depending upon the direction of rotation of thedrive screw 600.
• Thedisposable loading unit 16 may further include areturn switch 630 that is mounted in thehousing 200 and is adapted to be actuated by theknife nut 610. As can also be seen inFIG. 5, aswitch 640 is mounted in thehousing 200 and is also oriented to be actuated by theknife nut 610 to indicate when theanvil assembly 20 has been closed. Aswitch 650 is mounted in thehousing 200 and is also adapted to be actuated by theknife nut 610 to indicate that theaxial drive assembly 212 has moved to is finished position. The specific operations ofswitches 630, 640, 650 will be discussed in further detail below.
• FIG. 4 illustrates acircuit embodiment 700 of the present invention that illustrates the positions of various components of thedisposable loading unit 16 of the present invention when in a "pre-use" condition. For example, the various components of thedisposable loading unit 16 may be in this pre-use orientation when theunit 16 is being stored or shipped. As can be seen in that Figure, when in this orientation, thebattery contacts 528 and 530 do not contact any of thecontacts 540, 542, 544 in thehousing 200 which prevents thebattery 526 from being drained during non-use.
• FIGS. 5 and 6 illustrate the positions of various components of thedisposable loading unit 16 after it has been coupled to the elongated body 14 of the surgical cutting and staplinginstrument 10. In particular, as can be seen inFIG. 5, thedistal end 276 of thecontrol rod 52 has been coupled to thebattery holder 524. When thecontrol rod 52 is attached to thebattery holder 524, thebattery holder 524 is moved in the distal direction "DD" against thespring 550 such that thebattery contacts 528, 530 are brought into contact with thereturn contacts 540 in thehousing 200. Also, when in that position, theknife nut 610 actuates thereturn switch 630 into an open orientation. It will be appreciated that thereturn switch 630 is a normally closed switch that is actuated to the open position by theknife nut 610. As shown inFIG. 6, when thereturn switch 630 is open, themotor 562 is not powered.
• FIGS. 7 and 8 illustrate the positions of various components of thedisposable loading unit 16 after the clinician has actuated the movable handle 24 (shown inFIG. 1) of the surgical cutting and staplinginstrument 10. As discussed inU.S. Patent No. 5,865,361, when themovable handle 24 is initially moved toward the stationary handle member 22, thecontrol rod 52 is caused to move in the distal direction "DD". As can be seen inFIG. 7, as thecontrol rod 52 is initially moved in the distal direction during the anvil close stroke, thebattery holder 524 moves thebattery 526 to a position wherein thebattery contacts 528, 530 contact the anvilclose contacts 542. Power is now permitted to flow from thebattery 526 to themotor 562 which rotates thedrive screw 600 and causes thedrive beam 266 to move distally. As thedrive beam 266 moves distally in the "DD" direction, thecamming pin 286 engagescam portion 209 ofanvil portion 204 and causes theanvil assembly 20 to pivot to a closed position as illustrated inFIG. 7. As thedrive beam 266 moves distally to the anvil closed position, theknife nut 610 moves out of contact with thereturn switch 630 which permits the return switch to resume its normally open position. Theknife nut 610 then actuates the anvil closedswitch 640 and moves it to an open position. SeeFIG. 8. One or more anvil closed lights 660 may be mounted in thehousing 200 for providing a visual indication to the clinician that theanvil assembly 20 has been moved to the closed position.
• When the clinician desires to fire the instrument 10 (i.e., actuate theinstrument 10 to cause it to cut and staple tissue), the clinician first depresses theplunger 82 of the firing lockout assembly 80 (FIG. 1) as discussed inU.S. Patent No. 5,865,361. Thereafter,movable handle 24 may be actuated. As themovable handle 24 is depressed, thecontrol rod 52 moves thebattery holder 524 andbattery 526 to the position illustrated inFIGS. 9 and 10. As can be seen in those Figures, when thebattery 526 is moved into that position, thebattery contacts 528, 530 are brought into contact with thefire contacts 544. Theswitch 650 is normally closed until it is actuated by theknife nut 610. Thus, when thebattery contacts 528, 530 contact the firingcontacts 544, power flows from thebattery 526 to themotor 562 which drives thedrive screw 600. As thedrive screw 600 is rotated, thedrive beam 266 andknife nut 610 are driven in the distal direction "DD" to advanceactuation sled 234 throughstaple cartridge 220 to effect ejection of staples and cutting of tissue. Once thedrive beam 266 reaches the end of the firing stroke (i.e., all of the staples in thestaple cartridge 220 have been fired),knife nut 610 is positioned to actuate the normally closedswitch 650 and move it to an open position (illustrated inFIG. 10) which stops the flow of power from thebattery 526 to themotor 562.
  A distal indication light orlights 670 may be mounted on thehousing 200 to provide an indication to the clinician that thedrive beam 266 has reached its distal-most fired position.
• To retract thedrive beam 266, the clinician grasps the retract knobs 32 (shown inFIG. 1) on thehandle assembly 12 and pulls them in the proximal direction "PD". The operation and construction of the retractknobs 32 is discussed inU.S. Patent No. 5,865,361. Once the clinician moves the drive beam 266 a sufficient distance in the proximal direction "PD" so as to move the battery to contacts 540 (FIG. 11), power will be supplied throughswitch 630 to reverse themotor 562. Knife nut then releasesswitch 650. Themotor 562 then drives thedrive beam 266 distal to switch 630, which opens. Thereturn switch 630 is also in its normally closed position thereby permitting power to flow to themotor 562 and rotate thedrive screw 610 in an opposite direction to drive thedrive beam 266 in the proximal direction "PD". Once theknife nut 610 actuates theknife return switch 630, theknife return switch 630 is moved to an open position thereby stopping flow of power from thebattery 526 to themotor 562.
  A starting light 700 may be mounted in thehousing 200 to provide an indication that thedrive beam 266 is in the starting position.
• FIGS. 11 and 12 illustrate the positions of various components of thedisposable loading unit 16 of the present invention when the distal end of thedrive beam 266 andblade 280 inadvertently becomes jammed during the firing stroke (i.e., when theblade 280 is being distally advanced through the tissue clamped in the tool assembly 17). To address such occurrence, acurrent limiter 680 may be provided as shown inFIG. 12. Thecurrent limiter 680 serves to turn off themotor 562 when the amount of current that it is drawing exceeds a predetermined threshold. It will be understood that the amount of current that themotor 562 draws during a jam would increase over the amount of current drawn during normal firing operations. Once thecurrent limiter 680 shuts down themotor 562, the clinician can retract thedrive beam 266 by grasping the retract knobs 32 (shown inFIG. 1) on thehandle assembly 12 and pulling them in the proximal direction "PD" and themotor 562 will drive thedrive screw 600 in reverse in the manner described above. Thus, thecurrent limiter 680 serves to stop themotor 562 when theaxial drive assembly 212 encounters resistance that exceeds a predetermined amount of resistance which is associated with the predetermined maximum amount of current that themotor 562 should draw under normal operating circumstances. This feature also saves the battery power so thedrive beam 266 can be retracted.
• Thus, thedisposable loading unit 16 of the present invention comprises a self-contained motor driven disposable loading unit that may be used in connection with conventional surgical cutting and stapling instruments that traditionally required the clinician to manually advance and retract the drive assembly and cutting blade of a disposable loading unit coupled thereto. Various embodiments of thedisposable loading unit 16 may be constructed to facilitate the automatic retraction of the axial drive assembly should the blade encounter a predetermined amount of resistance.
• While several embodiments of the invention have been described, it should be apparent, however, that various modifications, alterations and adaptations to those embodiments may occur to persons skilled in the art . For example, according to various embodiments, a single component may be replaced by multiple components, and multiple components may be replaced by a single component, to perform a given function or functions. This application is therefore intended to cover all such modifications, alterations and adaptations without departing from the scope of the disclosed invention as defined by the appended claims.
• The invention which is intended to be protected is not to be construed as limited to the particular embodiments disclosed. The embodiments are therefore to be regarded as illustrative rather than restrictive. Variations and changes may be made by others without departing from the scope of the present invention as defined by the claims Accordingly, it is expressly intended that all such equivalents, variations and changes which fall within the scope of the present invention as defined in the claims be embraced thereby.

Claims (4)

1. A disposable loading unit (16) for attachment to a surgical cutting and stapling apparatus (10), said disposable loading unit (16) comprising:

   a carrier (216);

   a staple cartridge (220) supported in said carrier (216);

   an anvil assembly (20) movably coupled to said carrier (216) for selective movable travel between open and closed positions relative to said staple cartridge (220);

   an axial drive assembly (212) supported within said carrier (216) to move in a distal direction from a start position to an end position through said carrier and said staple cartridge (220) and in a proximal direction from said end position to said start position;

   a motor (562) supported within said carrier (216) and interfacing with said axial drive assembly (212) to drive said axial drive assembly In said distal and proximal directions;
   characterised by

   a battery holder (524) movably supported within said carrier (216) and attachable to a control rod (52) of the surgical cutting and stapling apparatus (10); and

   a battery (526) supported within said battery holder (524) such that said battery (526) is retained in a disconnected position prior to coupling said disposable loading unit (16) to the surgical cutting and stapling apparatus (10) and is movable therefrom to one of the subsequent connected positions upon coupling said disposable loading unit (16) to said surgical stapling apparatus (10).
2. The disposable loading unit (16) of claim 1 further comprising : an indicator (660, 670, 700) supported on said disposable loading unit (16) for indicating: (i) when said axial drive assembly is in a starting position; and/or (ii) when said anvil assembly is in said closed position; and/or (iii) when said axial drive assembly is In a distal-most position.
3. The disposable loading unit of claim (16) 1 further comprising means (680) for stopping said motor (562) from driving said drive assembly (212) In said proximal direction when said axial drive assembly (212) encounters resistance that exceeds a predetermined amount of resistance.
4. The disposable loading unit of claim 3 wherein said means for stopping said motor (562) comprises a current limiter (680) operably coupled to said motor (562).

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